REVIEW | doi:10.20944/preprints202305.0060.v1
Subject: Computer Science And Mathematics, Analysis Keywords: Interpolative convex contraction; Suzuki convex contraction; fixed point; fractional differential equation.
Online: 2 May 2023 (05:26:06 CEST)
The paper's main goal is to introduce a novel type of interpolative convex contraction and build up some fresh findings for it using the interpolative convex contractions' progressive approach. We have established certain conclusions using orbitally S-complete and Suzuki type contractions in F-metric spaces. My research aims to examine the fixed point method's efficacy in solving fractional differential equation with boundary conditions.
ARTICLE | doi:10.20944/preprints202208.0245.v1
Subject: Public Health And Healthcare, Physical Therapy, Sports Therapy And Rehabilitation Keywords: tensiomyography; gymnastics; contraction time; asymmetry
Online: 15 August 2022 (03:32:45 CEST)
Introduction: The purpose of this study was to determine the normative values of muscles’ contractile properties, lateral symmetry, and the impact of aging on muscle contractility in gymnastics. Materials and Methods: A survey of 81 athletes from different disciplines was undertaken: MAG (n = 26), WAG (n = 28), and RG (n = 27). The athletes’ average age was 15.41 ± 5.03 years. We try to establish the normative values for contraction time (muscle pairs) in gymnastics for Slovenian athletes for ten skeletal muscles. Results: Athletes’ age affects contractility in a negative way. Differences between the duration of contractility and age were found in all disciplines: m. BF (r = 0.48, p < 0.001), m. TB (r = 0.37, p < 0.013), m. ES (r = 0.17, p < 0.025), m. VL (r = 0.36, p < 0.00) and m. VM (r = 0.40, p < 0.000) at a statistical significance of p < 0.05. Conclusions: A comparison between the left and right sides shows little asymmetry in WAG and that the occurrence of injuries is in the middle range. In RG we see a bigger deviation, which could trigger the emergence of pain or injury in m. BF (13%) and m. GL (14.5%), but in MAG the deviation is greater in m. BB (12%), m. BF (11%) and m. GM (13%).
ARTICLE | doi:10.20944/preprints202305.0221.v1
Subject: Physical Sciences, Theoretical Physics Keywords: Lorentz contraction effect; Planck energy formula
Online: 4 May 2023 (07:57:09 CEST)
This paper is another applied article based on the author's "Unified Theory of Force". The main work of this paper is as follows: (1) Reinterpretation of the Lorentz contraction effect and rigorous proof that the Lorentz contraction is a physical phenomenon based on the conservation of energy and momentum under non-completely symmetrical relative motion effects. This paper proves that the Lorentz contraction effect not only occurs in the direction of motion but also simultaneously in any direction. (2) For the first time, we attempted to explain the physical meaning of the Planck energy formula in theory and associate the Planck energy formula with the Lorentz contraction effect, which can help us to have a deeper understanding of the true physical meaning behind the Planck energy formula. At the same time, we also made reasonable theoretical predictions about the basic structure of photons.
ARTICLE | doi:10.20944/preprints202112.0328.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: muscle strength; knee assessment; isometric contraction
Online: 21 December 2021 (12:32:53 CET)
The objective was to assess the instrumental validity and the test-retest reliability of a low-cost hand-held push dynamometer adapted from a load-cell based hanging scale (tHHD) to collect compressive forces in different ranges of compressive forces. Three independent raters applied 50 pre-established compressions each on the tHHD centered on a force platform in 3 distinct ranges: ~70 N, ~160 N, ~250 N. Knee isometric strength was also assessed on 19 subjects in two sessions (48h apart) using the tHHD anchored by an inelastic adjustable strap. Knee extension and flexion were assessed with the participant seated on a chair with the feet resting on the floor, knees, and hips flexed at 90°. The isometric force peaks were recorded and compared. The ICC and the Cronbach’s α showed excellent consistency and agreement for both instrumental validity and test-retest reliability, as the correlation and determination coefficients. The SEM and the MDC analysis returned adequate low values with a coefficient of variation less than 5%. The Bland-Altman results showed consistency and high levels of agreement. The tHHD is a valid method to assess the knee isometric strength, showing portability, cost-effectiveness, and user-friendly interface to provide an effective form to assess the knee isometric strength.
ARTICLE | doi:10.20944/preprints201608.0095.v1
Subject: Computer Science And Mathematics, Analysis Keywords: fixed point; dualistic partial metric; generalized contraction
Online: 9 August 2016 (11:28:16 CEST)
We introduce the notion of generalized contraction on dualistic partial metric spaces. A fixed point theorem for mappings satisfying above mentioned contraction is obtained. Some consequences of our result are obtained. We construct an example to demonstrate the effectiveness of our result among the corresponding results in partial metric spaces. Our results provide substantial generalizations and improvements of several well known results existing in the comparable literature. We discuss an application of our fixed point results to show the existence of solution of functional equations.
ARTICLE | doi:10.20944/preprints202008.0339.v1
Subject: Physical Sciences, Particle And Field Physics Keywords: pre-bounce ekpyrotic contraction; f(R) gravity; reconstruction
Online: 15 August 2020 (06:15:05 CEST)
Inspired by the work of S. D. Odintsov and V. K. Oikonomou, Phys. Rev. D 92, 024016 (2015) , the present study reports a reconstruction scheme for f (R) gravity with the scale factor a(t) µ (t * - t) c22describing the pre-bounce ekpyrotic contraction, where t is the big crunch time. The reconstructed f (R) is used to derive expressions for density and pressure contributions and the equation of state parameter resulting from this reconstruction is found to behave like "quintom". It has also been observed that the reconstructed f (R) has satisfied a sufficient condition for a realistic model. In the subsequent phase the reconstructed f (R) is applied to the model of chameleon scalar field and the scalar field f and the potential V(f) are tested for quasi-exponential ex pansion. It has been observed that although the reconstructed f (R) satisfies one of the sufficient conditions for realistic model, the quasi-exponential expansion is not available due to this reconstruction. Finally, the consequences pre-bounce ekpyrotic inflation i n f (R) gravity are compared to the background solution for f (R) matter bounce.
ARTICLE | doi:10.20944/preprints202005.0046.v1
Subject: Computer Science And Mathematics, Mathematics Keywords: fixed point; q-contraction; binary relation; integral equation
Online: 4 May 2020 (02:54:58 CEST)
In this paper, inspired by Jleli and Samet [journal of inequalities and applications 38 (2014) 2 1–8] we introduce two new classes of auxiliary functions and utilize the same to define (q, y)R-weak 3 contractions. Utilizing (q, y)R-weak contractions, we prove some fixed point theorems in the setting 4 of relational metric spaces. We employ some examples to substantiate the utility of our newly proved 5 results. Finally, we apply one of our newly proved results to ensure the existence and uniqueness of 6 solution of a Volterra-type integral equation.
ARTICLE | doi:10.20944/preprints202112.0095.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: coactivation; agonist; strength; muscular performance; dynamic contraction; eccentric; concentric.
Online: 6 December 2021 (19:29:42 CET)
Purpose: While resultant maximal voluntary contraction (MVC) is commonly used to assess muscular performance, the simultaneous activation of antagonist muscles could dramatically underestimate the strength of the agonist muscles. While quantification of antagonist torque has been performed in plantar- (PF) and dorsi-flexion (DF) joint in isometric conditions, it has yet to be determined in anisometric (concentric and eccentric) conditions. Methods: The experiment was performed in 9 participants through 2 sessions (reliability). The MVCs in DF and PF were measured in isometric, concentric and eccentric conditions (10°.s-1). Electromyographic (EMG) activities from the soleus, gastrocnemius medialis and lateralis, and tibialis anterior muscles were simultaneously recorded. The EMG biofeedback method was used to quantify antagonist torque, where participants were asked to maintain a level of EMG activity, corresponding to antagonist EMG activity and related to the muscle contraction type, according to a visual EMG bio-feedback displayed on a screen. Results: Resultant torque significantly underestimated agonist torque in DF MVC (30-65%) and to a lesser extent in PF MVC (3%). Triceps surae antagonist torque was significantly modified with muscle contraction type, showing higher antagonist torque in isometric (29 Nm) than eccentric (23 Nm, p < 0.001) and concentric (14 Nm, p < 0.001) conditions and resulting in modification of the DF MVC torque-velocity shape. The difference between DF eccentric and concentric MVC was attenuated when considered agonist torque (12%) rather than resultant torque (45%). Conclusion: Estimation of the antagonist torque in isometric or anisometric condition brings new insights to assessment of muscular performance and could result in costly misinterpretation in strength training and/or rehabilitation programs.
ARTICLE | doi:10.20944/preprints202004.0312.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: chalocomoracin; proliferative vitreoretinopathy; vitreous; Akt; p53; migration; proliferation; contraction
Online: 19 April 2020 (02:18:01 CEST)
Retinal pigment epithelial (RPE) cells are the major cell type in the epi- or sub-retinal membranes in the pathogenesis of proliferative vitreoretinopathy (PVR), which is a blinding fibrotic eye disease and still short of effective medicine. The purpose of this study is to demonstrate if Chalocomoracin (CMR), a novel purified compound from fungus-infected mulberry leaves, is able to inhibit vitreous-induced signaling events and cellular responses intrinsic to PVR. Our studies have revealed that the CMR IC50 for ARPE-19 cells is 35.5 μM at 72 hours, and that 5 μM CMR inhibits vitreous-induced Akt activation and p53 suppression; in addition we have discovered that this chemical effectively blocks vitreous-stimulated proliferation, migration and contraction of ARPE-19 cells, suggesting that CMR is a promising PVR prophylactic.
ARTICLE | doi:10.20944/preprints201807.0458.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: IR contraction; psaI gene duplication; Plastome; SSR; Croton tiglium; Euphorbiaceae
Online: 23 November 2018 (14:53:27 CET)
Croton L. (Euphorbiaceae) is a very specious genus and consists of about 1,250 species, mainly distributed in tropical Asia and China. The first complete plastome sequence from the genus, Croton tiglium, is reported in this study (NCBI acc. No. MH394334). The plastome is 150,021 bp in length. The lengths of LSC and SSC are 111,654 bp and 18,167 bp, respectively. However, the length of the IR region is only 10,100 bp and includes only four rrn and four trn genes, and a small part of the ycf1 gene. We propose two-step IR contractions to explain this unique IR region of the C. tiglium plastome. First, the IR contracted from rps19-rpl2 to ycf2-trnL-CAA on the LSC/IRb boundary. Second, the IR contracted from ycf2-trnL-CAA to rrn16-trnV-GAC on the LSC/IRa boundary. In addition, duplicated copies of psaI genes were discovered in the C. tiglium plastome. Both copies were located side by side between accD and ycf4 genes, but one copy was pseudogenized because of a five-basepair (TAGCT) insertion in the middle of the gene following frameshift mutation. The plastome contains 112 genes, of which 78 are protein-coding genes, 30 are tRNA genes, and four are rRNA genes. Sixteen genes contain one intron and two genes have two introns. The infA gene is lost. Twelve large repeats were detected in the plastome. All large repeats are located in the LSC region. Also, 272 simple sequence repeats (SSRs) were identified. The penta-SSRs accounted for 45% of total SSRs, followed by mono- (32%), di- (12%), tetra (6%) and tri-SSRs (5%). Most of them were distributed in the large single copy (LSC) region (85%). In addition, 76% of the SSRs were located in the intergenic spacer (IGS). Phylogenetic analysis suggested that C. tiglium is a sister group of Jatropha curcas with 100% bootstrap support. Seven Euphorbiaceae species formed one clade with 100% bootstrap support.
ARTICLE | doi:10.20944/preprints201809.0398.v1
Subject: Engineering, Control And Systems Engineering Keywords: DC-DC buck converter; contraction analysis; global stability; matrix norm
Online: 20 September 2018 (05:17:58 CEST)
Reliable and robust control of power converters is a key issue in the performance of numerous technological devices. In this paper we show a design technique for the control of a DC-DC buck converter with a switching technique that guarantees not only good performance but also global stability. We show that making use of the contraction theorem in the Jordan canonical form of the buck converter, it is possible to find a switching surface that guarantees stability but it is incapable of rejecting load perturbations. To overcome this, we expand the system to include the dynamics of the voltage error and we demonstrate that the same design procedure is not only able to stabilize the system to the desired operation point but also to reject load, input voltage and reference voltage perturbations.
ARTICLE | doi:10.20944/preprints201809.0226.v1
Subject: Computer Science And Mathematics, Analysis Keywords: Cauchy sequence; d-self-closed relation; relation contraction; relation preserving
Online: 13 September 2018 (03:16:34 CEST)
We obtain two generalizations of a known theorem of A. Alam and M. Imdad (Fixed Point Theory Appl. 17 (2015) 693–702) showing that some standard proofs can be obtained involving only Cauchy sequences of the successive approximations instead of the usual successive approximations sequences. Suitable examples prove the effective generalization of our results in metric spaces not necessarily complete.
ARTICLE | doi:10.20944/preprints201704.0048.v1
Subject: Social Sciences, Behavior Sciences Keywords: stress; transcranial magnetic stimulation; spinal reflex; reaction time; co-contraction
Online: 10 April 2017 (05:59:46 CEST)
The purpose of the present study was to investigate the effects of psychological pressure on corticospinal excitability, the spinal reflex, lower limb muscular activity, and reaction times during a task involving dominant leg movements. Ten healthy participants performed a simple reaction time task by raising the heel of their dominant foot from a switch. After 20 practice trials, participants performed 20 non-pressure and 20 pressure trials in a counterbalanced order. Stress responses were successfully induced, as indexed by significant increases in state anxiety, mental effort, and heart rates under pressure. Significant increases in motor evoked potential (MEP) amplitude of the tibialis anterior muscle (TA) occurred under pressure. In terms of task-related EMG amplitude, the co-contraction rate between the soleus (SOL) and TA muscles significantly increased along with SOL and TA EMG amplitudes under pressure. Hoffmann reflexes for SOL and reaction times did not change under pressure. These results indicate that corticospinal excitability and leg muscle-related EMG activity increase homogeneously during lower limb movements that are performed under psychological pressure.
ARTICLE | doi:10.20944/preprints201903.0056.v1
Subject: Physical Sciences, Particle And Field Physics Keywords: Relativity, EPR, Superluminal, Ether, Sudarshan, Effective mass, time dilation, length contraction
Online: 5 March 2019 (11:32:04 CET)
This paper seeks to investigate the questions of: How does the constancy of the speed of light come about? Why does time dilation and length contraction occur? Are they physical effects with a mechanism? Does mass have a role is in these effects? Is Relativity an emergent phenomenon? The enquiry is along a different tact than the standard Lorentzian invariance canon but in the realm of readily known experimental facts or analogies and theory in the domain of wave propagation and solid state physics. These analogies, to almost prosaic physics, have a small following and are called Ether Theories, which modern physics has implicitly reinstated by General Relativity and Quantum Field Theories. In the category of Ether Theories based on analogies to solid state physics, this presentation is unique in not being Lorentz invariant; it is based on earlier papers by the author enquiring into the speed of coincidence counting of the Bell Inequality and a communication protocol. It is believed that Lorentz invariance emerges from the Ether and all Relativistic Mechanics can be built from the bottom up. The conclusion is that space-time is not really curved but the effects are all ascribable to mass gain.
ARTICLE | doi:10.20944/preprints201812.0102.v1
Subject: Physical Sciences, Particle And Field Physics Keywords: Special relativity theory, length contraction, Planck length, Planck time, trans-Planck
Online: 10 December 2018 (13:43:34 CET)
In gravity theory, there is a well-known trans-Planckian problem, which is that general relativity theory leads to a shorter than Planck length and shorter than Planck time in relation to so-called black holes. However, there has been little focus on the fact that special relativity also leads to a trans-Planckian problem, something we will demonstrate here. According to special relativity, an object with mass must move slower than light, but special relativity has no limits on how close to the speed of light something with mass can move. This leads to a scenario where objects can undergo so much length contraction that they will become shorter than the Planck length as measured from another frame, and we can also have shorter time intervals than the Planck time. The trans-Planckian problem is easily solved by a small modication that assumes Haug's maximum velocity for matter is the ultimate speed limit for something with mass. This speed limit depends on the Planck length, which can be measured without any knowledge of Newton's gravitational constant or the Planck constant. After a long period of slow progress in theoretical physics, we are now in a Klondike "gold rush" period where many of the essential pieces are falling in place.
ARTICLE | doi:10.20944/preprints201809.0198.v1
Subject: Computer Science And Mathematics, Analysis Keywords: P-common best proximity point, weak Pp-property, S-weakly contraction.
Online: 11 September 2018 (12:26:16 CEST)
In this paper, we introduced many new notions and new contraction named as S-weakly contraction after that we obtained the p-common best proximity point theorems for different types of contractions in the setting of complete metric spaces by using weak Pp-property and proved the uniqueness of these points. Also we presented some examples to prove the validity of our results.
ARTICLE | doi:10.20944/preprints202303.0188.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: kinesiology tape; maximum isometric voluntary contraction; joint position sense; force sense; proprioception
Online: 10 March 2023 (08:50:49 CET)
(1) Background: Within the scope of prevention studies, many researchers have indicated the need to enhance knee proprioception. Kinesiology tape is one product that claims to enhance proprioception, however, its use has not been well researched in the healthy population before. The aim of the study was to investigate if kinesiology tape application on the quadriceps muscle enhances proprioception. (2) Methods: Twelve healthy and physically active volunteers (M=7, F=5, mean age= 20.75 ± 2.14, mean BMI=22.25 ±2.34) participated in the study. With computerized, custom-built isokinetic dynamometer, we recorded perceived joint position angles (small and large angles). For force sense, we recorded maximum voluntary isometric contractions (MVIC) and differences in torques (Nm) via force matching tasks both with vision and without vision on left leg. The absolute errors for joint position sense measurements and for force matching tasks and differences in MVIC both in untaped and taped conditions for left legs of all subjects were recorded. (3) Results: Two-way repeated measures ANOVA revealed that no significant interaction existed among small and large angle groups in both the conditions nor any main condition effect was observed in both the groups. (p>0.05). Similarly, no differences were accounted in force matching tasks between the taped and un-taped with vision and without vision (p=0.52 and 0.38 respectively.) Statistically insignificant increments were observed in mean torque post application. (p=0.67) (4) Conclusions: Present study suggests that immediate kinesiology tape application on quadriceps muscle offers no benefits on proprioception in terms of joint position sense and force sense hence other preventive measures to strengthen the proprioceptive system should be relied upon.
ARTICLE | doi:10.20944/preprints202203.0054.v1
Subject: Engineering, Bioengineering Keywords: electrocardiogram; K-means clustering algorithm; premature ventricular contraction; rule-based decision algorithm
Online: 3 March 2022 (07:22:36 CET)
Premature ventricular contraction (PVC) is one of the common ventricular arrhythmias, which may cause stroke or sudden cardiac death. Automatic long-term electrocardiogram (ECG) analysis algorithms could provide diagnosis suggestion even early warning for physicians, however, they are mutually-exclusive in terms of robustness, generalization and low complexity. In this study, a novel PVC recognition algorithm that combines deep learning-based heartbeat template clusterer and expert system-based heartbeat classifier is proposed. Long short-term memory-based auto-encoder (LSTM-AE) network was used to extract features from ECG heartbeats for K-means clustering. Thus, the templates were constructed and determined based on clustering results. Finally, the PVC heartbeats were recognized based on a combination of multiple rules, including template matching and rhythm characteristics. Three quantitative parameters, sensitivity (Se), positive predictive value (P+) and accuracy (ACC), were used to evaluate the performances of the proposed method on the MIT-BIH Arrhythmia database and the St. Petersburg Institute of Cardiological Technics database. Se on the two test databases was 87.51% and 87.92%, respectively; P+ was 92.47% and 93.18%, respectively; and ACC was 98.63% and 97.89%, respectively. The PVC scores on the 3rd China Physiological Signal Challenge 2020 training set and hidden test set were 36,256 and 46,706, respectively, which could rank first in the open-source codes. The results showed that the combination strategy of expert system and deep learning can provide new insights for robust and generalized PVC identification from long-term single-lead ECG recordings.
ARTICLE | doi:10.20944/preprints202104.0704.v1
Subject: Medicine And Pharmacology, Veterinary Medicine Keywords: Parascaris; carvacrol; nicotinic acetylcholine receptors; muscle contraction; electrophysiology; Xenopus oocytes; mode of action
Online: 27 April 2021 (10:54:16 CEST)
Parascaris sp. is the only ascarid parasitic nematode in equids and one of the most threatening infectious organisms in horses. Only a limited number of compounds are available for treatment of horse helminthiasis and Parascaris sp. worms have developed resistance to the three major anthelmintic families. In order to overcome the appearance of resistance, there is an urgent need for new therapeutic strategies. The active ingredients of herbal essential oils are potentially effective antiparasitic drugs. Carvacrol is one of the principal chemicals of essential oil from Origanum, Thymus, Coridothymus, Thymbra, Satureja and Lippia herbs. However, the antiparasitic mode of action of carvacrol is poorly understood so far. Here, the objective of the work was to characterize the activity of carvacrol on Parascaris sp. nicotinic acetylcholine receptors (nAChRs) function both in vivo with the use of worm neuro-muscular flap preparations and in vitro with two-electrode voltage-clamp electrophysiology on nAChRs expressed in Xenopus oocytes. We have developed a neuromuscular contraction assay on Parascaris body flaps and obtained acetylcholine concentration-dependent contraction responses. Strikingly, we observed that 300 µM carvacrol fully and irreversibly abolished Parascaris sp. muscle contractions elicited by acetylcholine. Conversely, carvacrol antagonized acetylcholine-induced currents from both the nicotine-sensitive AChR and the morantel-sensitive AChR subtypes. Thus, we show for the first time that the body muscle flap preparation is a tractable approach to investigate the pharmacology of Parascaris sp. neuro-muscular system. Our results suggest an intriguing mode of action for carvacrol being a potent antagonist of muscle nAChRs of Parascaris sp. worms which may account for its antiparasitic potency.
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: fundamental science; atomic nature; hard coating; expansion and contraction; force-energy behavior; surface and interface
Online: 2 April 2019 (12:41:20 CEST)
Coating of suitable materials having thickness of few atoms to several microns on a substrate is of great interest to the scientific community. Hard coatings develop under the significant composition of suitable-natured atoms where their force-energy behaviors when in certain transition state favour binding. In the binding mechanism of suitable atoms, electron belonging to outer ring filled state of gas-atom undertakes another clamp of energy knot belonging to outer ring unfilled state of solid-atom. Set process conditions develop the binding of different-natured atoms when processing their suitable composition in a system. Atoms of different nature develop structure in the form of hard coating by locating their ground points between the original ones. Here, gas-natured atoms increase the potential energy under decreasing levitational force of electrons, whereas, solid-natured atoms decrease the potential energy under decreasing gravitational force of electrons. In TiN coating, Ti–Ti atoms bind under the difference of expansion of their lattices, called nets of energy knots, where one atom just lands on the already landed atom. An adhered N-atom to a Ti-atom forms its position among four Ti-atoms where N-atom occupies the interstitial site of Ti-atoms. Two oppositely working force-energy behavior atoms deposit in the form of coating at substrate surface as per set conditions of the process. The rate of ejecting (or dissociating) solid-natured atoms depend on the nature of their source (target), process parameters and processing technique. In random arc-based vapor deposition system, depositing differently natured atoms at substrate surface depends on the input power. In addition to intrinsic nature of atoms, different properties and characteristics of coatings emerge as per engaged forces under their involved energy. The present study sets new trends in the field of coatings involving the diversified class of materials and their counterparts.
ARTICLE | doi:10.20944/preprints202209.0157.v1
Subject: Computer Science And Mathematics, Mathematics Keywords: ordered complete multiplicative GM−metric space; closed ball; integral equations; locally generalized ∆-implicit contraction
Online: 13 September 2022 (04:44:36 CEST)
In this paper, we introduced a generalized ∆-implicit locally contractive condition and give some examples to support it and to show its significance in fixed point theory. We prove that the mappings satisfying generalized ∆-implicit locally contractive condition admits a common fixed point, where, the ordered multiplicative GM−metric space is chosen as underlying space. The obtained fixed point theorems generalize many earlier fixed point theorems on implicit locally contractive mappings. In addition, some nontrivial and interesting examples are provided to support our findings. To demonstrate the originality of our new main result, we apply it to show existence of solutions to a system of nonlinear -Volterra type- integral equations.
ARTICLE | doi:10.20944/preprints202304.0112.v1
Subject: Environmental And Earth Sciences, Water Science And Technology Keywords: HEC-RAS model; Red River; LiDAR data; Flood mapping; Manning’s n-coefficient; Contraction Scour Depth
Online: 7 April 2023 (04:54:08 CEST)
This research is focused on two key areas. The first is mapping the 2022 flood in the Red River of the North near Grafton, North Dakota, US, and the second is evaluating the scour potential of the Grafton Bridge. Local scour of bridge piers can cause hydraulic structures such as bridge piers and abutments to fail during floods, making it a crucial area of investigation. To collect bathymetry and discharge data during low and high flow conditions, including a flood event with a 16.5-year return period in 2022, an Autonomous Surface Vehicle (ASV) incorporated with LiDAR DEM (Digital Elevation Model) data obtained from the US Geological Survey (USGS) National Map was used. Flood mapping and evaluation of local scour around the bridge pier were conducted using the HEC-RAS 6.0.0 software, which utilizes the Colorado State University method as a default equation. This research demonstrates the potential of ASVs in collecting critical data and LiDAR DEM data is an efficient method for flood mapping and determining scour potential, as it integrates bathymetry, flow velocity, and flood prediction.
ARTICLE | doi:10.20944/preprints202209.0433.v1
Subject: Computer Science And Mathematics, Analysis Keywords: Dilation, von Neumann inequality, Non-Archimedean valued field, p-adic Hilbert space, Contraction, Unitary operator
Online: 28 September 2022 (07:13:18 CEST)
We introduce the notion of p-adic magic contraction on p-adic Hilbert space. We derive p-adic Halmos dilation, p-adic Egervary N-dilation, p-adic von Neumann inequality and p-adic Sz.-Nagy dilation for p-adic magic contraction.
ARTICLE | doi:10.20944/preprints202108.0029.v1
Subject: Computer Science And Mathematics, Algebra And Number Theory Keywords: θ∗-weak contraction; fixed point; discontinuity at the fixed point; property P; matrix equation; integral equations
Online: 2 August 2021 (12:21:49 CEST)
In this paper, the notion of θ∗-weak contraction is introduced, which is utilized to prove some fixed point results. These results are helpful to give a positive response to certain open question raised by Kannan [Amer. Math. Monthly 76:1969] and Rhoades [Contemp. Math. 72:1988] on the existence of contractive definition which does not force the mapping to be continuous at the fixed point. Some illustrative examples are also given to support our results. As applications of our result, we investigate the existence and uniqueness of a solution of non-linear matrix equations and integral equations of Volterra type as well.
ARTICLE | doi:10.20944/preprints201810.0540.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: maximal voluntary contraction; peripheral fatigue; neuromuscular activation; femoral nerve electrical stimulation; critical peripheral fatigue threshold; electromyography
Online: 23 October 2018 (15:12:43 CEST)
We asked whether the level of peripheral fatigue would differ when three consecutive exercise trials were completed to task failure, and whether there would be delayed recovery in maximal voluntary contraction (MVC) force, neuromuscular activation and peripheral fatigue following task failure. Ten trained sport students performed three consecutive knee extension isometric trials (T1, T2, T3) to task failure without breaks between trials. T1 and T2 consisted of repeated 5-s contractions followed by 5-s rest. In T1, contractions were performed at a target force at 60% pre-exercise MVC. In T2, all contractions were MVCs, and task failure occurred at 50% MVC. T3 was a sustained MVC performed until force fell below 15% MVC. Evoked force responses to supramaximal electrical femoral nerve stimulation were recorded to assess peripheral fatigue. Electromyography signals were normalized to M-wave amplitude to assess neuromuscular activation. Lower levels of evoked peak forces were observed at T3 compared to T2 and T1. Within 5 s of task failure in T3, MVC force and neuromuscular activation recovered substantially without any recovery in evoked peak force. Neuromuscular activation 5-10 s after T3 was unchanged from pre-exercise values, but evoked peak forces were substantially reduced. These results challenge the existence of a critical peripheral fatigue threshold that reduces neuromuscular activation. Since neuromuscular activation changed independently of any change in evoked peak force, immediate recovery in force production after exercise is due to increased central recruitment and not to peripheral mechanisms.
ARTICLE | doi:10.20944/preprints201804.0007.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: pigment dispersion syndrome; pigmentary glaucoma; trabecular meshwork; phagocytosis; migration; contraction; cytoskeleton; gene microarray; Rho signaling pathway
Online: 2 April 2018 (07:00:45 CEST)
Purpose: To investigate the effect of pigment dispersion on trabecular meshwork (TM) cells. Methods: Porcine TM cells from ab interno trabeculectomy specimens were exposed to pigment dispersion, then analyzed for changes in morphology, immunostaining, and ultrastructure. Their abilities to phagocytose, migrate, and contract were quantified. An expression microarray, using 23,937 probes, and a pathway analysis were performed. Results: TM cells readily phagocytosed pigment granules. Pigment induced stress fiber formation (pigment (P): 60.1 ± 0.3%, n = 10, control (C): 38.4 ± 2.5%, n = 11, P < 0.001) and contraction at 24 hours onward (P < 0.01). Phagocytosis declined (P: 68.7 ± 1.3%, C: 37.0 ± 1.1%, n = 3, P < 0.001) and migration was reduced after 6 hours (P: 28.0.1 ± 2.3, n = 12, C: 40.6 ± 3.3, n = 13, P < 0.01). Microarray analysis revealed that Rho, IGF-1, and TGFβ signaling cascades were central to these responses. Conclusions: TM cell exposure to pigment dispersion resulted in reduced phagocytosis and migration, as well as increased stress fiber formation and cell contraction. The Rho signaling pathway played a central and early role, suggesting that its inhibitors could be used as a specific intervention in treatment of pigmentary glaucoma.
ARTICLE | doi:10.20944/preprints201902.0041.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Approximate Bayesian computation; demographic history; distributional shift; evolutionary history; machine learning; phylogeography; range contraction; range expansion; Reticulitermes flavipes; species distribution modeling
Online: 4 February 2019 (16:47:40 CET)
The eastern subterranean termite, Reticulitermes flavipes, currently inhabits previously glaciated regions of the northeastern U.S., as well as the unglaciated southern Appalachian Mountains and surrounding areas. We hypothesized that Pleistocene climatic fluctuations have influenced the distribution of R. flavipes, and thus the evolutionary history of the species. We estimated contemporary and historical geographic distributions of R. flavipes by constructing Species Distribution Models (SDM). We also inferred the evolutionary and demographic history of the species using mitochondrial (cytochrome oxidase I and II) and nuclear (endo-beta-1,4-glucanase) DNA sequence data. To do this, genetic populations were delineated using Bayesian spatial genetic clustering, competing hypotheses about population divergence were assessed using approximate Bayesian computation (ABC), and changes in population size were estimated using Bayesian skyline plots. SDMs identified areas in the north with suitable habitat during the transition from the Last Interglacial to the Last Glacial Maximum, as well as an expanding distribution from the mid-Holocene to the present. Genetic analyses identified three geographically cohesive populations, corresponding with northern, central, and southern portions of the study region. Based on ABC analyses, divergence between the Northern and Southern populations was the oldest, estimated to have occurred 64.80 thousand years ago (kya), which corresponds with the timing of available habitat in the north. The Central and Northern populations diverged in the mid-Holocene, 8.63 kya, after which the Central population continued to expand. Accordingly, phylogeographic patterns of R. flavipes in the southern Appalachians appear to have been strongly influenced by glacial-interglacial climate change.
ARTICLE | doi:10.20944/preprints202109.0291.v1
Subject: Physical Sciences, Theoretical Physics Keywords: relativistic energy; energy conservation law; Einstein’s principle of relativity; rest mass in wave motion; relativity of simultaneity; time dilation; Lorentz contraction; mechanical transverse wave; special relativity
Online: 16 September 2021 (14:20:57 CEST)
We study the effect of the generation of the mechanical transverse wave (MTW) travelling in the opposite direction (OD) to a moving medium (MM) on the relativistic energy conservation law (RECL). From the viewpoint of the relativity of simultaneity (RS), the time on the coordinate coinciding with the advance end of the wave (AEW) travelling toward the rear of the MM passes faster than that on the coordinate coinciding with the wave source (WS). Then the AEW in the MM travels forward compared to that in the rest frame of reference (RFR) which is stationary relative to the medium when the time on the coordinate coinciding with the WS is same for each inertial frame of reference (IFR). Hence, the coordinate interval (CI) between the AEW and WS in the MM is observed to be larger than that between them in the RFR. We show that this difference holds true for the CI of any portion having transverse velocities mutually converted by the Lorentz transformation (LT). This difference in the CI leads to that in the rest mass (RM). We demonstrate that the RM included in wave motion (WM) in the MM is larger than one included in WM in the RFR when comparing the portions having transverse velocities mutually converted by the LT. This relation holds true for all portions in WM. Therefore, the total coordinate interval of the portion (CIP) and total RM (TRM) included in WM in the MM (WMMM) are large compared to them included in WM in the RFR. Furthermore, we compare the relativistic kinetic energy (RKE) of the MTW travelling in the OD to the MM (ODMM) with that of the MTW propagating in the direction vertical to the moving direction of the medium. We prove that the CIP and RM included in the former MTW are larger than them included in the latter MTW when comparing each portion with the same transverse velocity (TV). Moreover, the total CIP and TRM included in the former MTW are also large compared to them included in the latter MTW. The reason for these is that the latter CIP and RM are equal to them in the RFR when comparing the portions having transverse velocities mutually converted by the LT. On the other hand, the energy supplied to generate each MTW is the same. From these, we demonstrate that the RKE of the MTW travelling in the ODMM can be larger than the total relativistic energy (TRE) of the MTW propagating in the direction vertical to the moving direction of the medium. Consequently, we propose a violation of the RECL and Einstein’s principle of relativity (EPR) because the TRE is not necessarily conserved in the IFR in which the medium is moving.
REVIEW | doi:10.20944/preprints201912.0412.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Frank-Starling; angiotensin receptor; muscle contraction; myosin light chain kinase; Protein Kinase C-βII; myosin light chain phosphatase; β-arrestin; MgATP; MgADP-phosphomyosin; myosin LC affinity for Ca2+
Online: 11 January 2020 (13:24:08 CET)
The involvement of the angiotensin II type 1 receptor in the Frank-Starling Law of the Heart, where the various activations are very limited, allows simple analysis of the kinase systems involved and thence extrapolation of the mechanism to that of angiotensin control of activation of cardiac and skeletal muscle contraction. The involvement of phosphorylation of the myosin light chain in the control of contraction is accepted but not fully understood. The involvement of troponin-I phosphorylation is also indicated but of unknown mechanism. There is no known signal for activation of myosin light chain kinase or Protein Kinase C-βII other than Ca2+/calmodulin but the former is constitutively active and thus has to be under control of a regulated inhibitor, the latter kinase may also be the same. Ca2+/calmodulin is not activated in Frank-Starling, i.e. there are no diastolic or systolic [Ca2+] changes. I suggest here that that the regulated inhibition is by myosin light chain phosphatase and/or β-arrestin. Angiotensin activation is by translocation of the β-arrestin from the sarcoplasm to the PM thus reducing its kinase inhibition action in the sarcoplasm, this reduced inhibition has been wrongly attributed to a mythical downstream agonist property of β-arrestin.